Incident to the high speed operation of machines of the kind referred to, considerable heat is generated by the reciprocation of sewing machine needles through a workpiece. The excessive heat of the needle, especially when sewing synthetic fabrics, may cause either melting of the fabric workpiece or the breaking of the thread passing through the needle eye. This condition is aggravated by the limited space requirements provided for placing a needle cooler relative to the needle but yet allowing operator access to the sewing area.
The purpose of this invention is to obviate these problems and to obtain greater efficiency and economy in operation of such machine. This purpose is accomplished by the provision of a pneumatically actuated mechanism operable, incident to machine operation, to biasably maneuver a needle cooling apparatus between an operative position, whereat a nozzle may be arranged closely adjacent the sewing machine needles to disperse a cooling medium thereagainst, and an inoperative position. In its inoperative position, the needle cooler is removed from the zone of the needles whereby providing operator access to the sewing area. The needle cooler is biased into its operative position under a constant but yielding pressure such that, if necessary, the nozzle may be temporarily displaced from the sewing area or zone but is then automatically returned to its operative position. A positive stop incorporated into the design of the needle cooler assures constant and proper positioning of the nozzles relative to the sewing machine needles. Because the present invention is activated incident to machine operation, the machine operator need not be concerned whether the needle cooler has been activated. In addition, means may be provided to automatically retract the needle cooler from its operative position upon completion of the sewing operation whereby allowing operator access to the machine.
In one form of the device, the needle cooler may include a distendable arm which carries the cooling nozzles toward the sewing zone of the machine. In its distended position, the arm may be arranged such that it extends proximate to and crosswise of the reciprocal path of the needles.
In line with all of the above, it is a primary object of this invention to provide a sewing machine needle cooler which, incident to machine operation, is maneuverable between a first disposition whereat a cooling medium is discharged against the sewing machine needles, and a second disposition, the latter position allowing operator access to the sewing area.
Another object of this invention is the provision of a needle cooler which is readily adapted to a wide range of machines, is inexpensive and economical in its operation.
A further object of this invention is to provide means operative to maintain the sewing machine needle cool while operating but which provides operator access to the sewing area when the machine is inoperative.
Another object of the invention is to provide a sewing machine needle cooling device which may be detachably secured to the sewing machine without significant alteration or modification of the machine itself.
It is a further object of this invention to provide a needle cooler which is biased into an operative position by a pneumatic system which allows the needle cooler to be temporarily displaced from its operative position and automatically returned thereto during the sewing operation.